Hide params from annotation type mismatches

crates/cli/tests/cli_run.rs

@@ -846,6 +846,57 @@ mod cli_run {
         )
     }
 
+    #[test]
+    #[cfg_attr(windows, ignore)]
+    fn module_params_bad_ann() {
+        check_compile_error_with(
+            CMD_DEV,
+            &cli_testing_dir("/module_params/bad_ann.roc"),
+            &[],
+            indoc!(
+                r#"
+                ── TYPE MISMATCH in tests/module_params/BadAnn.roc ─────────────────────────────
+
+                Something is off with the body of the fnAnnotatedAsValue definition:
+
+                3│   fnAnnotatedAsValue : Str
+                4│>  fnAnnotatedAsValue = /postId, commentId ->
+                5│>      "/posts/$(postId)/comments/$(Num.toStr commentId)"
+
+                The body is an anonymous function of type:
+
+                    Str, Num * -> Str
+
+                But the type annotation on fnAnnotatedAsValue says it should be:
+
+                    Str
+
+
+                ── TYPE MISMATCH in tests/module_params/BadAnn.roc ─────────────────────────────
+
+                Something is off with the body of the missingArg definition:
+
+                7│   missingArg : Str -> Str
+                8│>  missingArg = /postId, _ ->
+                9│>      "/posts/$(postId)/comments"
+
+                The body is an anonymous function of type:
+
+                    (Str, ? -> Str)
+
+                But the type annotation on missingArg says it should be:
+
+                    (Str -> Str)
+
+                Tip: It looks like it takes too many arguments. I'm seeing 1 extra.
+
+                ────────────────────────────────────────────────────────────────────────────────
+
+                2 errors and 1 warning found in <ignored for test> ms."#
+            ),
+        );
+    }
+
     #[test]
     #[cfg_attr(windows, ignore)]
     fn transitive_expects() {

crates/cli/tests/module_params/BadAnn.roc

@@ -0,0 +1,9 @@
+module { appId } -> [fnAnnotatedAsValue, missingArg]
+
+fnAnnotatedAsValue : Str
+fnAnnotatedAsValue = \postId, commentId ->
+    "/posts/$(postId)/comments/$(Num.toStr commentId)"
+
+missingArg : Str -> Str
+missingArg = \postId, _ ->
+    "/posts/$(postId)/comments"

crates/cli/tests/module_params/bad_ann.roc

@@ -0,0 +1,8 @@
+app [main] {
+    pf: platform "../fixtures/multi-dep-str/platform/main.roc",
+}
+
+import BadAnn { appId: "one" }
+
+main =
+    ""

crates/compiler/lower_params/src/type_error.rs

@@ -1,4 +1,4 @@
-use roc_can::expected::Expected;
+use roc_can::{expected::Expected, pattern::Pattern};
 use roc_module::symbol::{ModuleId, Symbol};
 use roc_region::all::Loc;
 use roc_solve_problem::TypeError;
@@ -32,9 +32,47 @@ pub fn remove_module_param_arguments(
     for error in errors {
         match error {
             TypeError::BadExpr(_, _, found, Expected::ForReason(reason, expected, _)) => {
-                remove_with_bad_expr_reason(&env, found, reason, expected);
+                remove_for_reason(&env, found, reason, expected);
             }
-            TypeError::BadExpr(_, _, _, _) => todo!("{:?}", error),
+
+            TypeError::BadExpr(
+                _,
+                _,
+                found,
+                Expected::FromAnnotation(
+                    Loc {
+                        value: Pattern::Identifier(name),
+                        region: _,
+                    },
+                    arity,
+                    _,
+                    expected,
+                ),
+            ) if env.is_extended(name) => {
+                if *arity > 1 {
+                    *arity -= 1;
+                }
+
+                drop_last_argument(found);
+                drop_last_argument(expected);
+
+                if let (
+                    ErrorType::Function(found_args, _, _),
+                    ErrorType::Function(expected_args, _, _),
+                ) = (found, expected)
+                {
+                    if found_args.len() > expected_args.len() {
+                        // If the found arity doesn't match  the annotation's, the params
+                        // record would appear in the error, so we replace it with `?`.
+                        if let Some(last) = found_args.last_mut() {
+                            *last = ErrorType::Error;
+                        }
+                    }
+                }
+            }
+
+            TypeError::BadExpr(_, _, _, Expected::FromAnnotation(_, _, _, _))
+            | TypeError::BadExpr(_, _, _, Expected::NoExpectation(_)) => {}
 
             // Irrelevant
             TypeError::BadPattern(_, _, _, _)
@@ -80,7 +118,7 @@ impl Env {
     }
 }
 
-fn remove_with_bad_expr_reason(
+fn remove_for_reason(
     env: &Env,
     found_type: &mut ErrorType,
     reason: &mut Reason,

crates/compiler/types/src/types.rs

@@ -3594,7 +3594,7 @@ pub enum Mismatch {
 
 pub type DoesNotImplementAbility = Vec<(ErrorType, Symbol)>;
 
-#[derive(PartialEq, Eq, Clone, Hash)]
+#[derive(PartialEq, Eq, Clone, Hash, Debug)]
 pub enum ErrorType {
     Infinite,
     Type(Symbol, Vec<ErrorType>),
@@ -3619,12 +3619,12 @@ pub enum ErrorType {
     Error,
 }
 
-impl std::fmt::Debug for ErrorType {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        // TODO remove clone
-        write!(f, "{:?}", write_debug_error_type(self.clone()))
-    }
-}
+// impl std::fmt::Debug for ErrorType {
+//     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+//         // TODO remove clone
+//         write!(f, "{:?}", write_debug_error_type(self.clone()))
+//     }
+// }
 
 impl ErrorType {
     pub fn unwrap_structural_alias(self) -> ErrorType {